Many animal brains also have magnetic particles, and there’s even some suggestion that animals use these particles to navigate. What’s more, a type of bacteria called magnetotactic bacteria use the particles to orient themselves in space.
2. A second brain in the gut?
Millions of brain cells live in the large intestine, and because these cells function without any instructions from the brain or spine, scientists sometimes refer to the mass of them as “the second brain.” But this mass also has a scientific name: the enteric nervous system. And a new study, done in mice, shows that the system is pretty smart; it can fire synchronized neurons to stimulate muscles and coordinate their activity so that it can do things like move feces out of the body.
The actual brain (the one in your head) can also do this — synchronize the firing of neurons — in the early stages of brain development. This means that the neuron actions in the gut could be a “primordial property” from the first stages of the second brain’s evolution. Some scientists even hypothesize that the second brain evolved before the first and that this firing pattern comes from the earliest functioning brain in the body.
3. A new kind of neuron
It’s not every day that scientists discover a completely new type of cell in the human brain, especially one that’s not found in neuroscientists’ favorite nonhuman subjects, mice. The “rosehip neuron,” so named because of its bushy appearance, had eluded scientists until this year, partly because it’s so rare.
This elusive brain cell makes up only about 10 percent of the first layer of the neocortex, one of the newest parts of the brain in terms of evolution (meaning the far-distant ancestors of modern humans didn’t have this structure). The neocortex plays roles in vision and hearing. Researchers don’t yet know what the rosehip neuron does, but they found that it connects to other neurons called pyramidal cells, a type of excitatory neuron, and puts the brakes on them.
4. U.D., the neuroscience patient
A boy, known in the medical literature as “U.D.” had one-third of the right hemisphere of his brain removed four years ago in order to reduce his debilitating seizures. The part of the brain that was removed included the right side of his occipital lobe (the brain’s vision-processing center) and most of his right temporal lobe, the brain’s sound-processing center.